In this world, there are a plenty of the similar cases that the perpetrators have been manipulated covertly through the electromagnetic wave, ended up with conducting mass murders.
However, it was quite hard to obtain the detailed situations as the most of the suspects were shot before making any confessions. It should make senses as the perpetrators have been so dangerous for the law enforcement to confront directly for the arrest. On the other hand, we just missed many pieces of evidence that they have been controlled externally.
We got dangerous ones down, but we let more dangerous ones free. The true culprits have been behind the electromagnetic wave and we had just missed an opportunity to track them down.
For example, I checked a detail of the Sandy Hook shooting case and there was almost no evidence left why the shooter killed many students. We cannot say the perpetrator was under the mind control, but this incident was a start of the tremendous increase of the school shooting. It implied something hidden, especially related to his motive.
At the same time, this incident took place just after the Senate select committee approved a report on the CIA torture case. This should be treated seriously at the spot in the intelligence community, but we have not known that fact as it was not available for the public until 2014.
This might be a coincidence but we might have more proofs if we had more evidence from the shooter; whether he was manipulated or not. This outcome would apply to any incidents potentially related to the electromagnetic wave.
Having said that, it was quite understandable to kill the suspects on the spot as they were dangerous to anyone including the law enforcement.